- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄16527 > XR20V2172L64-0B-EB (Exar Corporation)EVAL BOARD FOR XR20V2170 64QFN PDF資料下載
參數(shù)資料
| 型號： | XR20V2172L64-0B-EB |
| 廠商： | Exar Corporation |
| 文件頁數(shù)： | 2/51頁 |
| 文件大?。?/td> | 0K |
| 描述： | EVAL BOARD FOR XR20V2170 64QFN |
| 標(biāo)準(zhǔn)包裝： | 1 |
| 系列： | * |
第1頁當(dāng)前第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁
TABLE 5: IRQ# PIN OPERATION FOR RECEIVER
FCR BIT-0 = 0
(FIFO DISABLED)
FCR BIT-0 = 1
(FIFO ENABLED)
IRQ# Pin
HIGH = no data
LOW = 1 byte
HIGH = FIFO below trigger level
LOW = FIFO above trigger level
XR20V2172
10
TWO CHANNEL I2C/SPI UART WITH 64-BYTE FIFO AND RS232 TRANSCEIVER
REV. 1.0.2
2.6
Crystal Oscillator or External Clock Input
The V2172 includes an on-chip oscillator (XTAL1 and XTAL2) to produce a clock for both UART sections in the
device. The crystal oscillator provides a system clock to the Baud Rate Generators (BRG) section found in
each of the UART. XTAL1 is the input to the oscillator or external clock buffer input with XTAL2 pin being the
output. Please note that the input XTAL1 is not 5V tolerant and so the maximum at the pin should be VCC. For
programming details, see ““Section 2.7, Programmable Baud Rate Generator with Fractional Divisor” on
page 10.”
FIGURE 6. TYPICAL OSCILLATOR CONNECTIONS
C1
22-47 pF
C2
22-47 pF
Y1
1.8432 MHz
to
24 MHz
R1
0-120
(Optional)
R2
500Κ1Μ
XTAL1
XTAL2
The on-chip oscillator is designed to use an industry standard microprocessor crystal (parallel resonant,
fundamental frequency with 10-22 pF capacitance load, ESR of 20-120 ohms and 100 ppm frequency
tolerance) connected externally between the XTAL1 and XTAL2 pins (see Figure 6). The programmable Baud
Rate Generator is capable of operating with a crystal oscillator frequency of up to 24 MHz. Although the V2172
can accept an external clock of up to 64MHz, the maximum data rate supported by the RS-232 drivers is
250Kbps. For further reading on the oscillator circuit please see the Application Note DAN108 on the EXAR
web site at http://www.exar.com.
2.7
Programmable Baud Rate Generator with Fractional Divisor
Each UART has its own Baud Rate Generator (BRG) with a prescaler for the transmitter and receiver. The
prescaler is controlled by a software bit in the MCR register. The MCR register bit-7 sets the prescaler to divide
the input crystal or external clock by 1 or 4. The output of the prescaler clocks to the BRG. The BRG further
divides this clock by a programmable divisor between 1 and (216 - 0.0625) in increments of 0.0625 (1/16) to
obtain a 16X, 8X or 4X sampling clock of the serial data rate. The sampling clock is used by the transmitter for
data bit shifting and receiver for data sampling. The BRG divisor (DLL, DLM and DLD registers) defaults to the
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| UPM1E181MPD6TD | CAP ALUM 180UF 25V 20% RADIAL |
| AQ1051N8S-T | INDUCTOR 1.8NH 760MA 0402 SMD |
| UPS2G3R3MPD1TD | CAP ALUM 3.3UF 400V 20% RADIAL |
| XR20V2172L64-0A-EB | EVAL BOARD FOR XR20V2170 64QFN |
| UPJ1C331MPD6TD | CAP ALUM 330UF 16V 20% RADIAL |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| XR-210 | 制造商:EXAR 制造商全稱:EXAR 功能描述:FSK MODULATOR / DEMODULATOR |
| XR-2100CJ | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:MODEM |
| XR-2100CP | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:MODEM |
| XR-2103 | 制造商:EXAR 制造商全稱:EXAR 功能描述:FSK Modem Filter |
| XR-2103A | 制造商:EXAR 制造商全稱:EXAR 功能描述:FSK Modem Filter |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。